We have developed the single-strand linker ligation
method (SSLLM), which uses DNA ligase to add a double-stranded DNA linker to
single-stranded (ss) full-length cDNA. The linkers have random 6-bp (dN6
or dGN5) 3' overhangs that can ligate to any cDNA sequence, thereby
facilitating production of cDNA libraries with titers exceeding 1 x 106
independent clones. We confirmed that the 5' ends of cDNA inserts cloned by
using SSLLM are full-length and include the 5' UTRs. The great advantage of
our method is that elimination of the GC-tail simplifies the sequencing and
protein translation of the full-length clones. Further, our method tags ss cDNAs
more efficiently than does the traditional RNA ligase reaction.